(1) Field of the Invention
The present invention relates to a nitride semiconductor device, and particularly relates to a nitride light-emitting device.
(2) Description of the Related Art
Recently, light-emitting devices have been practically applied as a device using a nitride semiconductor (nitride semiconductor device). As such light-emitting devices, various types of high-brightness light-emitting diodes have been mass-produced to be applied as light sources for outdoor displays, car headlamps, indoor illumination, and so on. Likewise, semiconductor laser elements as light-emitting devices are often used as light sources for large-capacity disk storage devices. Particularly, the nitride semiconductor, which is a GaN-based material, is used for a high-brightness blue light-emitting diode or a blue-violate semiconductor laser element because it is possible to control a luminescence wavelength by adding indium (In) to GaN.
Normally, the nitride semiconductor light-emitting device is manufactured through various processes after epitaxially growing a luminescent layer including InGaN in a (0001) plane of the nitride semiconductor (see Non-Patent Reference 1: Barbara Neubert, and other two authors, “GaInN quantum wells grown on facets of selectively grown GaN stripes”, APPLIED PHYSICS LETTERS 87,182111(2005), American Institute of Physics). Normally, ammonia (NH3) is used as a nitrogen source for epitaxial growth. When using NH3 as the nitrogen source, an indium composition in InGaN is highest in the (0001) plane, and this effect has an advantage for shifting the luminescence wavelength toward a longer wavelength side. In addition, in recent years, a technique of epitaxially growing InGaN in a plane direction other than the (0001) plane has been actively developed.